Advise For FM Antenna?

[Dwight]

I have an old antenna about nine feet wide at the longest section.

It works well, and I dont need especially refined reception.

But it is ugly for my uphill neighbors to look at.

Can I install something smaller?

If so, what would you recommend?

Thanks very much in advance for your ideas.

Dwight Gibb

[professorpaul]

In ham radio, you are into the "stealth" antenna game. Not seen, not there... This is the standard problem when you are in a development with deed restrictions and can't have an outside antenna.

Consider one of these:

1. Feed your FM tuner from the cable network. Use a 75 ohm cable to

300 ohm twinlead transformer -- radio shack. You might also need a line splitter, in the event that you have a TV connected to the outlet you wish to use. If you have a "Type F" connector on the back of the FM receiver, then you don't need the balun transformer, and can feed it directly. This is usually the best bet, but be aware that some cable providers do not provide an FM signal over the cable. Make a call to tech support first.

1. If your reception is especially strong, just a piece of wire, 14 to

1/2 wavelength at the center of the FM band might suffice. There might be a connection on the back of the set, and a pigtail to ground the other side/screw terminal.

1. An inside dipole, fabricated to be 1/2 wavelength at the center of the FM band, and fed with 300 ohm twinlead at the center. Sometimes, these come already made up at places like Radio Shack. It takes about

10 minutes to make one. Just make sure the solder connections are good. Crimp on lugs on the feed line for a neat and good connection. Put the dipole up as high indoors as you can, and at 90 degrees to the station(s) you want to receive. If you can, put it in the attic.

Before you tear the old antenna down, try some of the above, and if they aren't to your satisfaction, the neighbors will have to live with it.

[Travis Jordan]

The size (in your case, length) of the antenna determines the gain. That antenna might or might not be overkill for your application. It depends on how far away the stations of interest are, their antenna elevation, your elevation, and what obstructions might be in the way. You could try mounting one of these in your attic (or outside if necessary) and see if it will do the job.

[tnom]

That all depends on how close you are to a major metropolitan area that may not require a directional and or gain antenna.

Are all the station in one direction?

Does your existing antenna have a rotor?

If you think you can get away without a gain or directional antenna then you can try this small omni directional antenna. You may even be able to hide it in the attic.

An antenna selector guide is located at the below link. It is for TV but it should give you an idea of just how much of an antenna you need. Other FM antenna choices are here.

[Phisherman]

Antennas that work well should not be touched. Getting an antenna just right can take a lot of trial-and-error effort. Plus, I found that the shape and price of an antennae is not directly related to the reception.

[Mark Lloyd]

You're likely to get someone who has no idea what you're talking about (at least the first one or two). If your FM receiver and TV are near each other, you could find it MUCH easier to try this than to take the "helpless option".

[snip]

[John]

Your old antenna doesn't sound like it's an FM antenna, unless the "nine feet wide" is the bar that the elements are connected to.

The FM wavelength is only a few inches wide. I don't have the figures handy, but I'm thinking less than 25" at the most. The higher the frequency you are trying to receive, the shorter the wavelength and so the shorter the antenna you need.

Using an antenna longer than the wavelength doesn't improve reception. If anything, it would be more likely to bring in interference from lower-frequency sources (which require longer antenna elements) if your FM receiver isn't good at rejecting other signals.

Additional (not longer) elements on the antenna, using the right length for FM, will improve reception; however, more elements will narrow the inward signal path. This could be useful to bring in a distant station and to eliminate signals coming in from other directions.

On the other hand, use less elements (like one or two) if you want to receive stations from a wide (not narrow) area. This will result in less reception from the direction the antenna is pointing towards but more reception from other directions.

There is no need to keep the antenna horizontal. The stations now transmit both horizontal and vertical polarity because they are allowed to transmit full power in both orientations at the same time, which is thought to increase their overall power to each orientation. So, you can mount your antenna vertically, if that would help in your choice. To get the most out of it, though, you wouldn't want to mount it any way other than horizontally or vertically.

John

[M Q]

...

... Uhh... Try about 3 meters. That's about 10 feet.

[Mark Lloyd]

Right. A dipole antenna is 1/2 wavelength long.

Also, the frequencies used by the FM broadcast band are just a little higher than TV channel 6 (that is, wavelength slightly lower). An antenna that works for TV-VHF (which I suppose the poster has) will work for FM too.

BTW, this closeness also explains what people often did in Rusk (where there is a TV station on channel 6). People could get the audio on their (not digitally tuned) FM radios.

[Dwight]

Thanks, John.

This is very helpful - it also explains why I am receiving pretty well after my antenna has blown off the chimney and lies on its side on the roof!

Best

[Dwight]

Looks good. Thanks.

[clifto]

Seems to me that if the phasing is right, a 45 degree angle would get you

41.4% more signal.